Optimization of Operating Variables of Molybdenite Column Flotation Using Factorial Design and Statistical Techniques

In this study, column flotation was used to recover high-grade molybdenite (MoS2) concentrate. Factorial design and statistical analysis were used to evaluate the relationships between the main variables affecting separation efficiency. The main variables were particle size (A), superficial gas velocity (E), depressant dosage (B), superficial wash water velocity (C), and frother concentration (D). MoS2 grades and recovery of 96.4% and 95.7%, respectively, were obtained under the optimized conditions. ANOVA results indicated that the primary variables affecting the MoS2 grade were in the following order: E > A > B > C. The interaction terms of AE and CE were identified as critical factors. The main variables affecting the MoS2 recovery were in the following order: C > B > D > E > A. The interactions of BC, BD, and CD were found to be significant. Furthermore, empirical model equations were derived to predict the grade (G) and recovery (R) based on column flotation variables. The optimal conditions were identified as A: 37.5 µm, B: 200 g/ton, C: 0.1 cm/s, D: 150 ppm, and E: 0.7 cm/s.